Reciprocating exercise device for shoulder strengthening

ABSTRACT

A reciprocating exercise device for strengthening of the muscles comprising the shoulder. The device is held in the user&#39;s hand and moved in a repeated manner to simulate a sports specific movement or for therapeutic muscle strengthening. A tube with detachable end caps contains a weight. The end caps house springs that extend into the tube when attached to the ends of the tube. The weight is of a diameter such that it may travel freely along the inner length of the tube, yet closely matched to the inner diameter of the tube such that significant air compression occurs in front of the moving weight. The generated air compression serves to reduce the shock of the weight when it impacts the springs at the tube ends. Controllable tube venting allow for control of the magnitude of this effect. Variable styles of attachable handles allow for improved simulation of sports specific throwing motions.

FIELD OF THE INVENTION

[0001] The invention is related to shoulder strengthening devices such as free weights and elastic bands and is more particularly directed to a spring-dampened, reciprocating, shoulder strengthening device.

BACKGROUND OF THE INVENTION

[0002] The shoulder joint is composed of a complex system of multiple muscles, tendons and ligaments. When functioning properly, these structures stabilize the head of the humerus within the Glenoid cavity. The four rotator cuff muscles surround the shoulder joint, blend with the capsule, and grasp their four points of attachment to the humerus, thus maintaining the integrity of the joint by acting as ligaments as well as moving the humerus.

[0003] Various exercise devices have been constructed to aid in the strengthening of the muscles that form the rotator cuff. The goal of such activity is to better stabilize the head of the humerus within the Glenoid cavity, especially during times of increased external loading as experienced during a throwing motion. Utilization of weighted dumbbells such as U.S. Pat. No. 460,270 issued to Somerby, U.S. Pat. No. 1,013,782 issued to Koch and U.S. Pat. No. 1,18,142 issued to Smith can be used to isolate and strengthen the muscles of the rotator cuff. However, strengthening achieved through dumbbell exercises does not fully prepare the shoulder joint for the type of loading seen during actual throwing activity. Dumbbell training does not simulate an actual throwing motion and therefore muscular development gained through such exercises may not be fully beneficial during actual throwing activities.

[0004] One general category of devices that have been proposed to strengthen the muscles of the rotator cuff is elastic band based designs. U.S. Pat. No. 4,268,031 issued to Schomburg describes a hoop with a hand-grip in its center with multiple elastic lines connecting the central handle to the parameter of the hoop. An oscillating motion is performed in an attempt to strengthen the muscles of the rotator cuff. This design only allows for a very short range of motion compared to the very long range of motion of an actual throwing movement. Utilizing similar elastic bands, U.S. Pat. No. 6,319,179 issued to Hinds describes a system of elastic cords that may be attached to a stable frame, such as a doorway. The cords pull against the general forward movement of the users hand during a typical throwing motion. Problems with this design include an unrealistic loading pattern for the throwing motion and the need of a stable frame for attachment.

[0005] Reciprocating movements of a weight can be used to strengthen the muscles of the rotator cuff Spring or metal strips can be utilized to produce the desired oscillating effect. U.S. Pat. No. 5,147,262 issued to Hymanson describes a thin metal strip that is held at its midpoint. The user moves their hand back and forth along a short linear path. The device provides acceleration and deceleration forces at the endpoints of this short range of motion movement. A drawback with this design is its inability to strengthen the appropriate muscle groups through a complete range of motion similar to one that is experienced during a throwing motion. U.S. Pat. No. 5,474,511 issued to Dantolan describes a rod with a weight that slides along the rod. Springs decelerate the moving weight as it approaches the rod handles. The handles are positioned at the ends of the rod. A problem with this design is that it does not allow for a relaxed, free-fall segment of the simulated throwing motion. Another problem concerns the inability for an accurate throwing motion to be performed given the positioning of the devices handles at the ends of a long rod. U.S. Pat. No. 3,545,121 issued to Misko describes a device similar to that of U.S. Pat. No. 5,474,511 but to be utilized as a toy rather than as a training tool. U.S. Pat. No. 5,674,162 issued to Ellingson describes a shoulder rehabilitation device that is based a design of a hollow hoop with a central hand grip where said hollow hoop contains a moveable weight. As the user generates the required hand motion to keep the weight traveling around the hoop the user's shoulder muscles are exercised. Shortcomings of this design include that it only allows for training over a relatively short range of motion and that the movements trained do not accurately simulate an actual throwing motion.

BRIEF SUMMARY OF THE INVENTION

[0006] To address the shortcomings of the available art, the present invention provides for shoulder musculature strengthening through a reciprocating motion consisting of an acceleration phase, followed by a “free-fall” phase, followed by a deceleration phase. The present invention provides the ability to simulate the three phases of a natural throwing motion while controlling many variables of that motion. Variables concerning said motion that can be uniquely controlled with the present invention include the mass of the weight thrown, the length of the “free-fall” phase, the degree of impact at the terminus of the deceleration phase and the degree of wrist involvement in the motion.

[0007] According to the invention, a shoulder strengthening, reciprocating device is composed of a rigid tube with springs fixed within the ends of the rigid tube and a weight mass positioned within the rigid tube and between the fixed springs. The device is used by grasping the tube and accelerating the device with the long axis of the tube oriented parallel to the direction of the user's hand movement. The shoulder complex is loaded during the acceleration phase of the movement. As the motion translates through a constant velocity phase and a deceleration phase, the weight mass within the tube slides from the back of the tube towards the front of the tube. At the endpoint of the motion, the hand has zero velocity but the weight mass continues to slide towards the spring fixed at the tube's end. As the weight mass impacts the fixed spring, the shoulder musculature must resist the forces generated due to the deceleration of the weight mass. The cycle of the motion is completed by then performing the reverse movement. Once again, a three phase loading of the shoulder is experienced. The end point of the reverse motion positions the user for the start of the next training cycle. The objective of the stated invention is to accurately and controllably simulate the forces placed upon the shoulder complex during throwing motions.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

[0008]FIG. 1: Cross-sectional view of device

[0009]FIG. 2: View of device as it would be attached to a subject's forearm

[0010]FIG. 3: View of device with optional short handle attachment

[0011]FIG. 4: View of device when configured with off-set handle attachment

[0012]FIG. 5: View of device when configured to be held at the tube midpoint

DETAILED DESCRIPTION OF THE INVENTION

[0013]FIG. 1 depicts a cross-sectional view of the preferred embodiment of the disclosed device. The device consists of a main tube (1) that contains a weight (2). It is preferred that the difference between the diameter of the weight (2) and the internal diameter of the main tube (1) should be no greater than 0.005 inches. The main tube (2) has threaded end caps (3) on both of its ends. The threaded end caps (3) have a spring (4) fixed rigidly into their bases. A practical method for securing said springs (4) involves embedding the ends of the springs into a body of acrylic resin (5) that has been poured into the inside cavity of the end caps. To allow for air flow in and out of the main tube (1) when the weight (2) travels within the tube, holes are drilled in the bottom of the end caps (6). An appropriate size for said holes is less than 0.5 inch diameter and greater than 0.05 inch diameter. Further air flow is allowed from the main tube (1) through auxiliary vent holes (7) drilled in the main tube (1). The auxiliary vent holes (7) may be opened or closed through rotation of an outer ring (8) that contains a hole (9). When said hole (9) is aligned with the auxiliary vent hole air flow into and out of the main tube (1) is allowed. Rotation of the outer ring (8) to a position where the hole (9) does not align with the auxiliary vent hole (7) prevents air flow. The functional importance of limiting the air flow into and out of the main tube (1) relates to its effect on the traveling velocity of the weight (2) within the main tube (1). Because of the closeness of fit between the internal diameter of the main tube (1) and the diameter of the weight (2), air within the main tube (1) is compressed ahead of the traveling weight creating a high pressure region and conversely the region behind the traveling weight is one of relatively low pressure. The pressure difference generates a force that opposes the momentum of the weight and functionally generates the feel of a softer impact to the user as the weight impact the spring. The ability to generate a softer impact is critical for use of the device by patients with significant damage to their shoulder joint and musculature. As the patient strengthens their shoulder complex the device can be adjusted to allow for less restricted air flow during use. This configuration of the device delivers a greater impact to the user due to a greater weight velocity given the same user motion. Handles (10) of various lengths and configurations may be attached to a T fixture (11) located along the main tube (1). The handle (10) may be secured to the T fixture (11) via a threaded coupling. Optionally, to allow for reduced strain on the user's wrist during utilization a strap (12) may be wrapped around the user's forearm. Said strap (9) may be secured by way of velcro attachment.

[0014]FIG. 2 illustrates the positioning of the device on a user's forearm when utilizing an extended handle length and a velcro forearm strap.

[0015]FIG. 3 illustrates the device when utilized with a shortened handle. The shortened handle generates greater strain on the user's wrist during operation when compared to the configuration shown in FIG. 2. The advantage of the shorter handle is that it tends to allow the user to replicate a more accurate throwing motion, therefore, generating more sports specific forces to strengthen the shoulder musculature.

[0016]FIG. 4 illustrates the device when utilized with an off-set handle attachment. The off-set handle attachment allows for further reduction in wrist stain during use. The off-set handle attachment also helps to position the hand and forearm in an orientation during device utilization that more closely replicates that seen during throwing activities.

[0017]FIG. 5 illustrates the device as it could be used without any handle. The main tube is grasp in a central location and a repeating motion is made by the user's hand along a path inline with the long axis of the device. A device configuration as shown in FIG. 5 may be used during the early phases of patient rehabilitation. 

What is claimed:
 1. A reciprocating weight exercise device that consists of: a tube with removable end caps that house springs; a weight mass that is of a size to travel within the tube.
 2. The exercise device of claim 1 in which a handle is attached perpendicularly to the tube; wherein said handle may extend approximately the length of a forearm to relieve partial loading from the user's wrist during device usage or may be of a shorter length to function as only a hand grip.
 3. The exercise device of claim 1 in which the end caps have holes drilled through their bases to allow air to be pushed out and pulled into the tube's interior cavity during device utilization.
 4. The exercise device of claim 1 in which the tube has a number of holes drilled through its walls to allow air to be pushed out and pulled into the tube's interior cavity during device utilization; additionally, sleeves may be used that can be moved along to tube length such that they may be positioned to completely block air flow through said holes, partially block air flow through said holes or completely expose said holes.
 5. The exercise device of claim 1 in which the weight mass is of a diameter such that it may travel unhindered along the tube length when propelled from gravity or weight momentum; and yet of a diameter such that the air space between the weight and the inner tube wall is small enough to generate significant air compression in the interior of the tube in front of the traveling weight; significant air compression being defined as that which is great enough to be easily noticed by feel by the device user. 